#include <iostream>

using namespace std;

class Vector2D
{
private:
    double x , y;
public:
    Vector2D( double iniX = 0 , double iniY = 0 )
    {
        x = iniX;
        y = iniY;
    }
    void Show()
    {
        cout << "(" << x << "," << y << ")" << endl;
    }
    Vector2D& operator + ( Vector2D& refVec )
    {
        x = x + refVec.x;
        y = y + refVec.y;
        return *this;
    }
};

int main()
{
    Vector2D d1( 3.5 , 4.5 ),d2( 2.5 , 5.5 ),d3( 0.0 , 0.0 );
    d3 = d1 + d2;
    d3.Show();
    return 0;
}
